Joss Whedon is in the unique position of being both a cult icon and a huge mainstream creator, thanks to projects like Firefly and The Avengers. But both halves of his success spring from his ability to create addictive stories, that leave you desperate to know what happens next.

We were lucky enough to spend some time chatting with Whedon at Comic Con, so we asked him some geeky questions about storytelling. Here's what he told us.

This interview was very kindly set up by Dark Horse Comics, so we tried to keep the interview pretty focused on the comics that Whedon is doing with them — including Buffy the Vampire Slayer Season 9, Angel and Faith, and some upcoming Firefly comics. But we also took this opportunity to geek out about comics versus other media, and the nature of serialized storytelling.

You've said in the past that TV shows are a question, and movies are an answer. What are comics?

I will put comics in the TV camp, because of the serialized storytelling, the growth over the years... but at the end of the day, you do sort of come to them needing a thing that is both cinematic and has that kind of resolve. So... both. I feel like when Spider-Man defeats the Tarantula, you get your answer. But then you need to know where he's going from there. And could I have made more of a Seventies reference than that? In my mind, it's all Ross Andru. But I think it's definitely both. Because you don't just want to move forward. You want something that says, "I'm here for this hero to win the day." The way you go see a movie and say, "I want that resolve."

That kind of feeds into our next question. Historically, both TV and comics depended on the illusion of change. You were part of a generation that challenged that, adding more arc-based storytelling and actual change. Like, Buffy graduates high school, drops out of college, moves to San Francisco, and so on. Do you think that was a good move, in retrospect?

It was good for us. It was good for the kinds of storytelling that I want to do. Is it good for all comics? I don't think so. Some things really should stay the same. Reed Richards should always have exactly this much gray. [Gestures at the sides of his head.] But um... You know, the problem is, when something goes on for as long as most things have, then they're just looking for any change. Either they reboot it, or they do something drastic, because they can't write the same thing over and over. I mean, TV shows don't run since the Sixties. Whereas some of these comics have.

But with the newer stuff, the more graphic novel-y stuff, when you get a story that's just about the progression of the story, for me it's harder to dive in than when I know, "This guy is going to have this power and that's the thing." It's a different experience. And for me, I feel like comics — that sort of comfort food that I refer to a lot of recent TV as — I seem to want that from comics.

You want the comfort food.

A little bit. I want to see the costume. I want to see the power. I want to know what the sitch is. And from there, I like the comfort food... but there's a lot of exceptions. Like with the Luna Brothers' Girls, which was a book that I never knew from issue to issue what was going to happen. I just adored it. But when I think about creating comics, I think more in terms of, "Why are we coming back? What do I love?" Not, "What can I change?".

When a character makes the transition from film to TV to comics, like Buffy, or comics to film like the Avengers, what is gained and what's lost in those transitions between media?

Well, you know... A ton of stuff gets gained and lost, obviously. Every medium is different, you have to respect that. Let's use the Avengers as an example. The wardrobe — on the one hand, you absolutely have to respect what people understand as iconically that character. On the other hand, some of that stuff looks idiotic. You can't give Captain America the big swashbuckler boots that he has in the comic, because they look dumb. And so you're always looking for what you can pull. And one of the things I give Marvel a lot of credit for is, they're good at knowing, "This is sacred. This is something we can approximate. And this, we don't need."

And, you know, with Buffy going to comics, what you lose are actors who actually are changing. They are growing. They are aging. They are investigating their characters in new ways. You know, you're just drawing old pictures of a person from reference. Luckily, Georges [Jeanty] is a master at doing reference that feels fresh. That doesn't feel like an old reference. But you know, you're always going to find there's a huge amount [that gets lost]. The trick is knowing what things are sacred.

In Season 8 of Buffy, I lost one of the sacred things, which is "This is about us." But I kept... I mean, I love Season 8. I think there's good stuff in it. But I felt there was one element that belonged in both [the TV show and the comics]. And with The Avengers, it was the same thing. The real question was, "Can I evoke the ethos and the feeling I had when I cracked that book every month when I was 11? And at the same time make a grown-up movie?"

What would Buffy Season 20 look like?

I think the real question is, "What will Buffy season 20 look like?" A little creaky. She's probably going to have some work done. Some Botox. You know... I am trying to think. She would be in her thirties. And believe me, there's a lot of stories to tell about that. Actually, it's sometimes easier to tell stories about people in their thirties than people in their twenties.

So you feel that Season 8 lost sight of the relatability of the characters?

A little bit. I was so excited by what a comic book can do that a TV show can't, that I lost a little bit of that thing of "What was sacred," what must go from one thing to the other.

So this is kind of a weird question, and you probably answered it years ago. But why did you choose not to retell Buffy's origin in the pilot of the TV show? Why pick up where the movie left off?

I don't like to tell the same story twice. Now, I repeat myself all the time. I have the same themes that I go to. And I have more than once actually written the same scene twice and then realized it too late. One time I caught it, and one time it aired. That was awkward. But I really don't... Once I've told a story, I kind of want to move on. And I didn't feel [like retelling it], even though not many people had seen Buffy the Vampire Slayer [the movie].

I was also creating a show, and movie to show is a very big change. To answer a question... the movie could just be a pastiche of horror movies. It was supposed to be a real horror movie — but in the way that Cabin [in the Woods] is, it was supposed to be a commentary on horror movies. And that was enough of a premise for a movie. It's not enough of a premise for a TV show. So I needed to introduce a completely new world anyway. I needed sidekicks anyway. And I needed to make her younger anyway, because she would have graduated [from high school too soon]. And so all of that led to me going, "I just want a new story."

And this was before everybody rebooted everything. This was before Ultimate Everything. And so maybe now, I'd go, "Oh, we'll just start again." Because people do that. But for me, I'm like, "I told that story. And I get bored."

Do you think you'll go back to TV at some point?

I absolutely hope so. I love TV, in a way that I don't love any other medium. But it's a huge commitment, and right now I just got out of a huge commitment. And I'm trying to figure out what my next one will be.

So when Angel moved from IDW to Dark Horse, he crossed universes. Is there something about crossing universes in that way that turns someone evil?

Well, you know, you just don't want to do it. You cross universes [and] first of all going through Security is hell. OK, and you usually get a horrible stomach. And the lag. It's really evil-lag, is what it is. So the most important thing for me, and I can't say enough — I thought IDW really did a wonderful job, and was also enormously gracious about the fact that for me, I just needed [Buffy and Angel] to be back on the same network. And then, for me, it was also like, if we're going to do that, we have to ring a change.

And how evil he was or wasn't, or thought he was, is the cause of some debate — even among the writers. I'm not sure we agree. I'm not sure all of us could totally follow the story [in season 8.] Is that a problem? [laughs]

Later on during Comic Con, we ran into Whedon at the Entertainment Weekly party, and took the opportunity to ask him just two more questions...

Is there anything you can tell us about Dr. Horrible 2?

Not a huge amount. Because we're still building it. And we don't want to give away the plot. And we're not even sure of the platform.

People like Tom Hanks and Bryan Singer are starting to create webseries now. Do you feel like this is a vindication of your faith in that format?

I felt vindicated the moment we finished filming it and I liked it. And other liked it, that was good too. And other people are doing it, that's fine, I guess. But I think everybody's got their own reasons, their own agenda, their own story to tell. It was important for us to do it on the internet. But what comes next — I'll be more interested in what the people with no established identities at all get to make than what we all can already make.